This invention relates generally to lay-in diffusers, and more particularly, to an insulated lay-in diffuser which is capable of resisting heat transfer.
In many constructions, suspended ceiling systems are used to finish a permanent structure which has been formed. Such suspended ceiling systems generally include a network of runners which are suspended from the permanent structure to form a desired pattern, and a plurality of corresponding ceiling panels which are positioned over and between the array of runners to provide a finished appearance.
Often, a number of components are located within the space defined between the suspended ceiling system and the permanent structure to which it is attached. This would include duct work for any air conditioning and heating systems which are to be provided. To permit communication between this duct work and the area located beneath the suspended ceiling, lay-in diffusers are often provided which are capable of resting upon and extending between the array of runners used to support the ceiling panels in position. Such diffusers generally include finished bottom portions provided with appropriate ventilating structures, and duct drops are generally provided to connect the duct work with those lay-in diffusers which are being used to ventilate an area.
Although such systems are easy to install and provide adequate operational capabilities, such systems can present certain problems in relation to the field of fire protection. For example, ceiling panels are available which are capable of providing a suitable barrier between the spaces located above and below the suspended ceiling system. Also available are a number of damper assemblies which can provide such a capability. For example, reference is made to those damper constructions described and illustrated in my U.S. Pat. No. 4,146,048, dated Mar. 27, 1979; U.S. Pat. No. 4,241,748, dated Dec. 30, 1980; U.S. Pat. No. 4,263,930, dated Apr. 28, 1981; and the damper construction disclosed in my U.S. patent application Ser. No. 117,125 abandoned, filed Jan. 31, 1980, the subject matter of each of which is incorporated by reference as if fully set forth herein. However, difficulties are still encountered in obtaining a diffuser which is fully capable of withstanding the conditions presented by a fire, hampering the development of a fully fire-rated ceiling system.
It therefore remains desirable to develop a lay-in diffuser which is capable of resisting the effects of a fire, and which therefore permits the development of a suspended ceiling system which is fully fire-rated.